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<html lang="zh-cn">
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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>设计模式demo - 购物车</title>
</head>
<body>
  <p>慕课网-霜月老师-前端设计模式-1</p>
  <p>慕课网-霜月老师-前端设计模式-2</p>
  <p>慕课网-霜月老师-前端设计模式-3</p>

  <button id="btn1">

  </button>


    <script type="text/javascript">
    </script>
</body>
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